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Radiochemistry Unit - Radiochemical Analyses Table of Contents | Ordering | Collection Kits | Price Schedule | Analysis | Test Interpretation | Radon Information | Health Information | Decay Chains | Research | DNR Quarterly Reports | Useful Links
Air Analyses Gross Alpha/Beta Purpose: Rapid screening test to determine if air samples show alpha or beta contamination. The test does not pick up contamination by radioactive substances that are pure gamma emitters. It is not possible to determine the levels of radioactivity from specific isotopes with this test. The source of the alpha/beta contamination can be natural or man-made. The Radiochemistry Unit performs gross alpha/beta air analyses for the Wisconsin Department of Public Health and Family Services (DHFS). Samples are collected from strategic locations around nuclear power plants in Wisconsin and bordering Wisconsin. Air is drawn through a filter for about one week using a special pump. The samples are sent to the lab via the U.S. mail where they are placed on a laboratory instrument that measures the amount of alpha and beta radioactivity on the filter. This is not a test for the average home owner. Purpose: Rapid screening test to determine the air concentration of radon 222. Radon is a naturally occurring radioactive substance. See also: Consumer Research Council (CRC), Wisconsin Radon Information Centers The radiochemistry lab offers a two day screening type kit. This kit contains a plastic vial with a small insert containing charcoal and a desiccant to absorb moisture. When the sample is received at the lab, a chemical called liquid scintillation cocktail is added directly to the plastic vial. The vial is allowed to sit for at least 12 hours before it is placed in a laboratory instrument that measures the amount of radon in the vial. It is critical to follow the instructions on the lab form as closely as possible to ensure an accurate result. The Radiochemistry lab is certified by National Environmental Health Association National Radon Proficiency Program (NEAA-NRPP) listed to perform short term passive radon 222 testing. Labs that are RMP listed have demonstrated proficiency in the measurement of radon in air. Some states have additional requirements for radon testing providers. Therefore, the WSLH radiochemistry lab can only perform radon analyses on samples taken in the following states:
Contact the Wisconsin Radon Information Center (RIC) hotline 1-888-569-7236 or the Consumer Research Council hotline 1-800-644-6999 for providers in other states. This is a suitable test for a home owner. The US Environmental Protection Agency recommends that all homes have the air tested for radon. Soil, Silt, and Sludge Purpose: To determine the presence of gamma emitting isotopes in solid materials such as soil, sand, sediment, and sludge. The method can be adapted to most solid materials that can be ground or chopped into small pieces. The source of the gamma contamination can be natural or man-made. For this analysis, dried and finely ground sample is placed in a container specifically designed for gamma scans. The container is sealed and then it is stored for 30 days before it can be analyzed. A gamma scan identifies and quantifies radioactive elements that give off gamma rays. Pure alpha and beta emitters are not measured by this analysis. This is a nondestructive test and the sample can therefore, be returned if desired. This test is not suitable for a home owner. Gross Alpha/Beta Purpose: To determine the presence of alpha and beta emitting isotopes in solid materials such as soil, sand, sediment, and sludge. The source of the alpha/beta contamination can be natural or man-made. A small amount of dried and finely ground material is placed a stainless steel disc and then put on a laboratory instrument that measures the amount of alpha and beta radioactivity in the sample. The activity of specific isotopes can not be determined. This test is not suitable for a home owner. Radium 226 in Sludge Purpose: To determine the radium 226 activity of waste water treatment sludge. Radium 226 is a naturally occurring radioactive substance. Radium 226 in sludge can be determined either by the gamma scan technique described above or by using a chemical method. For the chemical analysis, a small portion of dried and finely ground sample is processed chemically. The method relies on the fact that radium 226 decays into radon 222. Radon 222 is a radioactive gas that is easily measured using a radiation detection system known as a scintillation detector. The scintillation detector detects and counts the flashes of light that are produced when a radioactive substance interacts with the special coating on the inside of the container that holds the radon 222. Once a determination is made as to how much radon 222 is in the sample, the radium 226 can be determined mathematically. This test is not suitable for a home owner. Water Analyses [Safe Drinking Water Act (SDWA)] Purpose: To determine the presence of gamma emitting isotopes in drinking water. The source of the gamma contamination can be natural or man-made. This is a rapid method for the identification and quantification of gamma emitting isotopes in drinking water. The method can not be used to quantify gamma emitting isotopes that require the establishment of secular equilibrium between the parent isotope and its progeny. About 1 gallon of the water sample is put in a container specifically designed for gamma scans and analyzed on an instrument called a gamma spectrometer. This test would only rarely be recommended for a private home owner after consulting with the lab and the Wisconsin Division of Public Health - Radiation Protection Section Purpose: A screening test to determine the presence of alpha and beta emitting isotopes in drinking water. The source of the alpha/beta contamination can be natural or man-made. This screening test is used to determine if a public drinking water source has radioactive substances in it that give off alpha or beta radioactivity. It is not possible to determine the specific isotopes that are contributing to the alpha or beta activity with this test. About 200 milliliters of water is evaporated until only a small quantify of liquid remains. This concentrated liquid is transferred to a stainless steel disc and then heated until all of the remaining liquid is evaporated. Then remaining solids on the disc are then placed on a laboratory instrument that measures the amount of alpha and beta radioactivity in the sample. In Wisconsin, public water supplies are screened once every four years for gross alpha/beta activity. The Wisconsin Department of Natural Resources (WDNR) is responsible for maintaining the testing schedule, contacting water suppliers when their system needs testing, and enforcement of the regulations. If the gross alpha result is less than 5 pico curies per liter (pCi/L), the water is considered safe and no further testing is done for four years. If the result is greater than 5 pCi/L, the WDNR determines a schedule for additional testing and possible remediation. In Wisconsin, the majority of public water supplies that have elevated gross alpha activity are found along the eastern border from Green Bay down to the Illinois border. Some private wells in this area (and other parts of the State) may have elevated gross alpha activity. However, since most private wells are not as deep as public water supplies, private wells in this area are not as prone to the problem. This test is suitable for a home owner to have done if there is a concern about the possibility of radioactivity in their well. It is recommended that the home owner contact the lab (608-224-6227) for advice before ordering this test. The WDNR and the DHFS are also excellent resources for advice. Purpose: To determine the presence of radium 226 and radium 228 in public drinking water. Radium 226 and 228 are both naturally occurring radioactive substances. This chemical analysis is used to specifically determine the activity of radium 226 and radium 228 in drinking water. The radium 226 method relies on the fact that radium 226 decays into radon 222. Radon 222 is a radioactive gas that is easily measured using a radiation detection system known as a scintillation detector. The scintillation detector detects and counts the flashes of light that are produced when a radioactive substance interacts with the special coating on the inside of the container that holds the radon 222. Once a determination is made as to how much radon 222 is in the sample, the radium 226 can be determined mathematically. Radium 228 is determined by chemically separating its immediate progeny , actinium 228 (actinium 228 emits beta particles). The actinium is precipitated as a solid material (co-precipitated with yttrium as an oxalate) and transferred on to a stainless steel disc. This disc is then placed on a laboratory instrument that measures the amount of beta radioactivity on the disc. The radium 228 activity can be determined mathematically from the actinium 228 activity. If the gross alpha screening result is above 5 pCi/L, the WDNR requires analyzsis for radium. To determine if a public water supply exceeds the allowable level for radium, the activity from radium 226 is added to the activity from radium 228. The current value for an excedance is 5 pCi/L. This test may be suitable for a home owner with a private well under certain conditions. The lab or the WDNR or DHFS should be contacted for advice before proceeding with this test. Purpose: To determine the presence of radon 222 in drinking water. Radon 222 is a naturally occurring radioactive substance. Radon 222 is determined using a technique known as liquid scintillation analysis. A proper analysis is dependent on sample collection technique. Since radon 222 is a gas, it is easily lost from the sample if care is not taken while collecting and analyzing the sample. About 15 milliliters of the sample is injected beneath a special chemical called a liquid scintillation cocktail. The cocktail produces a flash of light that can be seen by a liquid scintillation analyzer when it interacts with a radioactive particle. Currently, there is no standard for radon 222 in water. Almost all water supplies (public and private) have measurable amounts of radon 222 in them. However, only the north central part of Wisconsin is known to have significantly elevated levels. For a private well owner the DHFS recommends action only if the radon 222 activity is 10,000 pCi/L or greater. This test is suitable for a private well owner. Purpose: To determine the presence of Strontium 89 and 90 in drinking water. Strontium 89 and 90 are man-made byproducts of the nuclear industry. This is a long and involved chemical analysis. Strontium 90 is determined by chemical separating its progeny, yttrium 90 (yttrium 90 emits beta particles). The yttrium is precipitated as a solid material (yttrium oxalate) and transferred on to a stainless steel disc. This disc is then placed on a laboratory instrument that measures the amount of beta radioactivity on the disc. The strontium 90 activity can be determined mathematically from the yttrium 90 activity. Strontium 89 is determined mathematically from the total strontium activity and the strontium 90 activity. This test is not suitable for a private well owner under normal circumstances. Purpose: To determine the presence of tritium isotopes in drinking water. Tritium is both naturally occurring and a man-made byproduct of the nuclear industry. Tritium is determined by first distilling a water sample to obtain pure water (removes the minerals and other solids). A 10 milliliter portion of sample is transferred to a vial containing liquid scintillation cocktail. The cocktail produces a flash of light that can be seen by a liquid scintillation analyzer when it interacts with a radioactive particle. This test is not suitable for a private well owner under normal circumstances. Purpose: To determine the presence of naturally occurring uranium in drinking water. Natural uranium is separated from a 500 milliliter water sample using an ion exchange technique. The uranium is captured on the ion exchange resin (similar to water softening resins) as the water sample passes through the resins. The uranium is than released from the resin with a weak acid solution. The acid solution is transferred to a stainless steel disc and placed on a laboratory instrument that measures the amount of alpha radioactivity in the sample. This test is required if the gross alpha result is over 15 pCi/L. Some private wells in the north central part of the State have been found to have total uranium levels in excess of 350 pCi/L. This test may be suitable for a private well owner under certain conditions. Contact the lab, WDNR or DHFS before ordering this test.
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